Heteroaromatic sulfonamide compounds are useful compounds in various fields as medicinal and agrochemical products and organic materials, or as raw materials and intermediates thereof. In particular, the compounds have recently been reported to be useful as medicinal products, and a safe and convenient production method is still desired (for example, see Non-Patent Document 1).
As a synthesis method of a heteroaromatic sulfonamide compound, a number of methods for producing a sulfonamide compound by reacting heteroaromatic sulfonyl chloride with amine have been reported until now (for example, see Patent Document 1 and Non-Patent Document 2).
In addition, as a synthesis method of a heteroaromatic sulfonamide compound, a method for producing a sulfonamide compound by the reaction of amine with heteroaromatic sulfonyl chloride which has been made using heteroaromatic sulfonic acid and phosphorus pentachloride (PCl5) or phosphorous oxychloride (POCl3) has been reported (for example, see Patent Document 2).
As a synthesis method of a heteroaromatic sulfonamide compound, a method for producing a sulfonamide compound by the reaction of amine with a heteroaromatic sulfonyl chloride which has been made from heteroaromatic thiol as a starting material using sodium hypochlorite or trichloroisocyanuric acid has been reported (for example, see Non-Patent Document 3 and Non-Patent Document 4).
On the other hand, a synthesis method of a heteroaromatic sulfonamide compound by reacting a mixed sulfonic acid anhydride of heteroaromatic sulfonic acid and p-nitrobenzene sulfonic acid with amine has been reported. (for example, see Non-Patent Document 5)